During the 1640 reconstruction, the chapel of Santa Catalina, which originally existed outside the walls, was demolished and was integrated to the walls of the structure, resulting in the alternate name Santa Catalina's Palace.

Initially, the structure consisted of four walls enclosing an interior
patio with a circular tower known as the Homage Tower. From the top of the tower, the governor, following military tradition, would take oaths of fidelity at critical moments to the King and Queen of Spain. Later, a second tower named the Austral Tower was constructed.

At present, the complex consists of a few attached buildings with formal living quarters in the second floor, and private quarters in the third. It overlooks the high city walls that front the
bay, and within the north perimeter of the house are sheltered gardens and a swimming pool.

History

La Fortaleza on a 1937 U.S. stamp

Since the 16th century, La Fortaleza has acted as the residence of the Governor of Puerto Rico, making it the oldest executive mansion in continuous use in the Americas.[3] On November 27, 1822, its traditional status as the executive mansion was made official. The fortress underwent a massive reconstruction in 1846 to change its military appearance into a
palatial facade. La Fortaleza has been the residence of more than 170 governors of Puerto Rico and has hosted various dignitaries, including President
John F. Kennedy and his wife
Jacqueline Kennedy who stayed in La Fortaleza in 1961.
King Juan Carlos of Spain and Queen
Juliana of the Netherlands are among several heads of state who have stayed in La Fortaleza. In June 2011, U.S. President
Barack Obama visited the mansion during a brief trip to the island marking the first visit of an in-office US President to the Fortaleza as well as the Island on official business since Kennedy, 50 years previously to that date.
King Felipe VI and
Queen Letizia of Spain also visited La Fortaleza in 2016.

1625, General Boudewijn Hendrick (Balduino Enrico) of the Netherlands invaded the city and established himself at La Fortaleza. During the Dutch retreat, the fortress and the city were set ablaze.

According to tradition, in 1898, just before the
United Statesinvaded Puerto Rico during the
Spanish–American War, the last
Spanish governor of the island, Ricardo De Ortega, struck a
longcase clock in La Fortaleza with his sword, stopping the clock and marking the time at which Spain lost control over Puerto Rico.

On October 30, 1950, there was an attempt by a few nationalists to enter La Fortaleza in what is known as the
San Juan Nationalist revolt, intending to attack then-governor
Luis Muñoz Marín. The 5-minute shootout resulted in four Nationalists dead: Domingo Hiraldo Resto, Carlos Hiraldo Resto, Manuel Torres Medina and Raímundo Díaz Pacheco. Three of the guards of the building, among them Lorenzo Ramos, were seriously injured.

On May 26, 2004, a man armed with a knife entered the mansion's mailroom located just outside the palace gates and took a receptionist hostage. The 2½ hour stand-off ended after Governor
Sila María Calderón entered the building and listened as the hostage-taker read a letter.